1 /* 2 * Copyright (C) 2008, 2009 Apple Inc. All Rights Reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #ifndef SmallStrings_h 27 #define SmallStrings_h 28 29 #include "UString.h" 30 #include "WriteBarrier.h" 31 #include <wtf/FixedArray.h> 32 #include <wtf/OwnPtr.h> 33 34 namespace JSC { 35 36 class HeapRootMarker; 37 class JSGlobalData; 38 class JSString; 39 class MarkStack; 40 class SmallStringsStorage; 41 42 static const unsigned maxSingleCharacterString = 0xFF; 43 44 class SmallStrings { 45 WTF_MAKE_NONCOPYABLE(SmallStrings); 46 public: 47 SmallStrings(); 48 ~SmallStrings(); 49 emptyString(JSGlobalData * globalData)50 JSString* emptyString(JSGlobalData* globalData) 51 { 52 if (!m_emptyString) 53 createEmptyString(globalData); 54 return m_emptyString; 55 } 56 singleCharacterString(JSGlobalData * globalData,unsigned char character)57 JSString* singleCharacterString(JSGlobalData* globalData, unsigned char character) 58 { 59 if (!m_singleCharacterStrings[character]) 60 createSingleCharacterString(globalData, character); 61 return m_singleCharacterStrings[character]; 62 } 63 64 StringImpl* singleCharacterStringRep(unsigned char character); 65 66 void markChildren(HeapRootMarker&); 67 void clear(); 68 69 unsigned count() const; 70 singleCharacterStrings()71 JSString** singleCharacterStrings() { return &m_singleCharacterStrings[0]; } 72 73 private: 74 static const unsigned singleCharacterStringCount = maxSingleCharacterString + 1; 75 76 void createEmptyString(JSGlobalData*); 77 void createSingleCharacterString(JSGlobalData*, unsigned char); 78 79 JSString* m_emptyString; 80 JSString* m_singleCharacterStrings[singleCharacterStringCount]; 81 OwnPtr<SmallStringsStorage> m_storage; 82 }; 83 84 } // namespace JSC 85 86 #endif // SmallStrings_h 87